An incrementally extendable telescopic mounting did form the subject matter of patent application FR 2898179.
Such a telescopic support presents however various drawbacks.
The resistance of the stops to pressure is only determined by their respective cylindrical arc lengths.
The resistance of the stops to sagging is structurally ensured by the laying out of set-in cylinders onto the respective telescopic elements internal bases, the thickness of said cylinders being, moreover, limited by the injected material characteristics.
The extension range of such a support is limited by the need to provide for of enough residual overlap of its two cylindrical elements, male and female, in order to ensure the preservation of a perfect alignment between their respective axes when the close to maximum support extension is reached, viz. when the guide lug passes through the descending/ascending loop segment junctions before and after reaching the highest incremental device extension level.
This insufficient overlap between male and female elements can generate, on the one hand, frictions which are detrimental to the gravity only device extension, on the other hand, guide lug jamming, resulting from the non upright positioning of its axis, relative to the male element axis, and relative, accordingly, to the bottom of the U shaped segment cross-section, but also due to the insufficiently slanted slopes of the descending and subsequently ascending segments which the guide lug follows before and after the support reaches its maximum extension level, at which level the resistance to downward pressure is ensured by a single couple of mating stops having a slightly greater stop length.
Because of their positioning at the stop cylinder upper end, said mating stops are moreover prone to sagging.
Finally, considering the present state of the art, for a telescopic support according to prior art and designed with more than one high level, the cumulative resting, on top of each other, of all the mating stops cannot be guaranteed.